KR101934252B1 - Piston pump for delivering fluids, and associated vehicle brake system - Google Patents

Abstract

The present invention relates to a fluid delivery piston pump comprising a piston, a cylinder member (5), and a pressure chamber (5.2) disposed between the inlet valve and the discharge valve (10) Is closed by a cover (16), and in the fluid flow (18) behind the discharge valve, a throttle means (10) of the fluid flow (18) is provided. The present invention also relates to a vehicle brake system with said piston pump. According to the present invention, the throttle means 10 comprises a movable ring disk 14 guided in a cylinder member 5, the inner diameter of the ring disk being aligned with the outer diameter of the cylinder member 5, 14 establishes a variable first throttle cross-section.

Description

TECHNICAL FIELD [0001] The present invention relates to a piston pump for a fluid delivery pump and an associated vehicle brake system,

The present invention relates to a piston pump for fluid delivery according to the preamble of independent claim 1. The present invention also relates to a vehicle brake system having the piston pump.

Piston pumps are known in the prior art as various embodiments. For example, a vehicle brake system often employs a radial piston pump having a plurality of pump members for delivering pressure media, wherein at least one piston in the radial piston pump is reciprocatable by an eccentric body. Typically, the so-called pump members consist of a piston, a piston operating surface often formed as a cylinder, an inlet valve and an outlet valve, and a sealing member. The valves are used for fluid control during pumping of the piston. In this case, the inlet valve is used to reflux the fluid into the inlet chamber during the compression phase, and the outlet valve prevents back flow of fluid from the pressure side into the pump interior chamber. Typically, the valve is formed as a ball valve subject to spring loading, and a discharge channel for the discharge valve is formed by a so-called discharge valve cover and a pump cylinder, and the discharge valve is accommodated in the discharge valve cover.

Open publication DE 10 2008 002 740 A1 discloses a piston pump for controlling the brake pressure in a hydraulic vehicle brake system, for example. The disclosed piston pump includes a pump housing, a receiving bore for a piston pump disposed in the pump housing, and a valve cover that closes the receiving pump against the outside, wherein the valve cover includes first and second channels Section is accepted. Because the venting structure affects the noise behavior of the piston pump, an appropriate tapering of the venting channel, which usually exhibits a throttle effect, is effected.

Open publication DE 10 2006 027 555 A1 discloses, for example, a piston pump with reduced noise generation. The disclosed fluid-dispensing piston pump includes a piston, a cylinder member, and a pressure chamber disposed between the inlet valve and the outlet valve. The pressure chamber is closed by a cover, the discharge valve includes a closed body embodied as a ball, a pre-stressing device acting on the closed body and embodied as a helical spring, a base member for supporting the pre-stressing device, And the sealing sheet of the discharge valve is disposed in the disc member. By the use of the disc member it is to be ensured that the part tolerance of the various parts of the piston pump can not adversely affect the discharge valve, in which case the assembly space for the pre-stressing device, embodied as a closed body and helical spring, It demands a big place.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a throttle means and, consequently, a piston pump for fluid delivery, in which the assembly space for a piston pump can be minimized.

The above object is achieved by the piston pump for fluid delivery according to claim 1.

The piston pump according to the present invention for delivering fluid comprising the features of independent claim 1 has the advantage that the throttle means and therefore the assembly space for the piston pump can be minimized.

The embodiment of the present invention can reduce the internal pressure of the piston pump, preferably in a high viscosity state of the fluid, by the elastic ring disk. As a result, the load of the drive output and the force transmitting discrete parts, such as bearings, pistons, high-pressure seal rings, etc., can preferably be reduced. This can be used to reduce cost in designing in future configurations.

The essence of the present invention is that the throttle means is arranged outside the piston pump, preferably the assembly space required for the piston pump is preferably reduced. Alternatively, the assembly space previously supported in the piston pump can be used as a damper chamber or as a mounting space for other damper elements. In this case, the throttle means comprises a ring disk, the ring disk is slid onto the pump cylinder and is guided by the pump cylinder, and the axial travel distance of the ring disk sets the variable first throttle cross section.

A piston pump according to the present invention for delivering fluid includes a piston, a cylinder member, and a pressure chamber disposed between the inlet valve and the outlet valve, wherein the pressure chamber is closed by a cover, , Throttle means of said fluid flow are provided. According to the present invention, the throttle means comprises a movable ring disk guided on a cylinder member, the inner diameter of the ring disk being adapted to the outer diameter of the cylinder member, and the axial travel distance of the ring disk being set to a variable first throttle cross- do.

The piston pump according to the invention can be used, for example, in a vehicle brake system for delivery of pressure media.

A preferred improvement of the fluid delivery piston pump as set forth in independent claim 1 is possible by the measures presented in the dependent claims.

It is particularly preferred that the ring disk comprises at least one opening which fixedly predefines the second throttle cross-section. The second throttle cross-section can preferably be optimized for volumetric flow at a predetermined temperature range. The second throttle cross-section can be optimized for volume flow, for example, in the temperature range of 0 ° C to 120 ° C. Due to the temperature fluctuations, the viscosity of the fluid and hence the flow resistance in the ring disk changes. As a result, the ring disk is further moved in the axial direction so that the free cross section is enlarged or a new free cross section is set by the preliminary stress device. As a result, the internal pressure of the pump does not rise, preferably at a particularly low temperature, and other parts of the piston pump are not damaged.

In a preferred embodiment of the piston pump according to the invention, the pre-stressing device comprises a ring disk for axial throttling of the fluid flow guided through the at least one outlet between the cover and the cylinder member, Lt; / RTI > The pre-stressing device is preferably implemented as a spring member, and the selected spring characteristics of the pre-stressing device define the axial travel distance of the ring disk. Thus, the pre-stressing device can be implemented as a spiral spring and / or a flat spring and / or a leaf spring and / or a shaft ring, for example. Thus, the prescribed spring force urges the ring disk in an axially sealing manner to the cover. In this case, the spring force is selected so that the throttle cross-section can be set by the axial movement distance of the ring disk. The dynamic throttle means acts by the ratio of the spring force / distance.

In another preferred embodiment of the piston pump according to the invention, the means for supporting the pre-stressing device embodied as a spring member is embodied as a ring shoulder on the circumference of the cylinder member. The ring shoulder is preferably implemented simply by inwardly directed projections on the periphery of the cylinder member.

In another preferred embodiment of the piston pump according to the invention, the end face of the cover forms a throttle point.

According to the present invention, there is provided a piston pump for fluid delivery in which the throttle means and thus the assembly space for the piston pump can be minimized.

Embodiments of the invention are shown in the drawings and described in detail in the following description. In the drawings, the same reference numerals indicate components or members that perform the same or similar functions.

1 is a schematic perspective view of an embodiment of a piston pump according to the present invention for delivery of a fluid;
Fig. 2 is a diagonal cross-sectional view of the rear region of the piston pump according to the invention shown in Fig. 1 for delivery of fluid; Fig.

1 and 2, a piston pump 1 according to the present invention for delivering a fluid includes a piston 3, a cylinder member 5, a sealing member 7, and a fluid filter 9 , The fluid filter (9) is disposed in front of an invisible inlet, and an invisible inlet valve is disposed behind the inlet. A pressure chamber 5.2 is disposed inside the cylinder member 5 between an unshown inlet valve and an unillustrated discharge valve and the pressure chamber 5.2 is closed by a cover 16, A valve is disposed. Only one sealing sheet of the discharge valve arranged in the outlet (5.4) of the pressure chamber 5.2 is shown. In addition, the discharge valve generally includes a closed body, a pre-stressing device acting on the closed body, and means for supporting the pre-stressing device. In order to reduce the generation of noise, throttle means 10 of the fluid flow 18 are provided in the fluid flow 18 behind the discharge valve.

The cover 16 can be manufactured by cutting or molding in a known manner, and a molding method is provided for mass production from an economical point of view. The venting structure is suitably formed because it affects the noise behavior of the piston pump. This design is an appropriate tapering of the discharge channel, which usually exhibits a throttle effect, in piston pumps known in the prior art. A hydraulic low-pass is formed by the throttle effect, and the low-pass contributes positively to undesirable noise generation. The behavior of the dynamic viscosity of the brake fluid at 0 to 120 DEG C can be regarded as almost constant and an optimum throttle effect is defined for the temperature range. As a result of the large change in the kinematic viscosity of the brake fluid over the required temperature range of -40 DEG C to 120 DEG C, the throttle places a load on the piston pump and the parts subject to the compressive load of the entire pump drive, especially at low temperatures. The narrowed cross-section leads to a greatly increased liquid friction at low temperatures, which leads to a severe transient increase in pump pressure and hence the abovementioned load.

According to the invention, the throttle means 10 comprises a movable ring disk 14 guided on a cylinder member 5, and the inner diameter of the ring disk is adapted to the outer diameter of the cylinder member. In this case, the axial movement distance of the ring disk 14 sets the variable first throttle cross-section. The piston pump (1) according to the present invention may be arranged, for example, in an unillustrated receiving bore of a pump housing or a fluid block. The transversely extending pressure medium channels lead into the receiving bore and the fluid through the pressure medium channel is directed towards the inlet of the piston pump 1 via the fluid filter 9 or at least one of the piston pumps 1 Is guided away from the discharge port (16.6).

As shown in Figures 1 and 2, the pre-stressing device 12 has a dynamic throttling of the fluid flow 18 guided through at least one outlet 16.6 between the cover 16 and the cylinder member 5 And presses the weir ring disc 14 against the throttle point 16.4 disposed in the cover 16. In the illustrated embodiment, the pre-stressing device 12 is embodied as a leaf spring. Alternatively, the pre-stressing device can be implemented as a helical spring and / or a flat spring and / or a shaft ring. The fluid can be directed from the discharge valve seat 20 to the outlet 16.6 upon opening of the discharge valve through the plurality of fluid channels 16.2.

2, the ring disk 14 is guided through the guide surface 14.2 of the cylinder member 5 and is axially guided by the pre-stressing device 12 in the starting state by a sealing surface 14.4, 16 and the throttle point 16.4 is formed by the end face of the cover 16 in the illustrated embodiment. The axial travel of the ring disk 14 is defined by the selected spring characteristics of the pre-stressing device 12. [ In addition, the means 5,6 for supporting the pre-stressing device 12 embodied as spring members are embodied as a ring shoulder around the cylinder member 5 in the illustrated embodiment.

Additionally, the ring disc 14 may include at least one opening that fixedly defines the second throttle cross-section. The second cross-section can be optimized for volumetric flow in a predetermined temperature range. That is, the second throttle cross-section can be optimized for volume flow, for example, in the temperature range of 0 ° C to 120 ° C. Due to the temperature change, the viscosity of the fluid changes and thus the flow resistance at the fixed predetermined second throttle cross-section of the ring disk 14 changes. Thereby, the ring disk 14 is further moved in the axial direction, whereby the free cross section is enlarged by the preliminary stress device 12 or a new free cross section is set. Because of this, the internal pressure of the piston pump 1 preferably does not rise particularly preferably at a low temperature, so that the other parts of the piston pump 1 are not damaged.

Embodiments in accordance with the present invention enable optimal utilization of available space and very good NVH-characteristics. By the elastic ring disk, the internal pressure of the piston pump in the high viscosity state of the fluid can be preferably reduced. This reduces the load on the drive output, and on the force transfer individual components, such as bearings, pistons, high-pressure seal rings, and the like. This can be used to reduce cost in designing in future configurations.

3 piston
5 cylinder member
5.2 Pressure Chamber
10 Throttle means
12 Preliminary stress device
14 ring disk
16 cover
16.4 Throttle point
18 fluid flow

Claims (10)

A piston pump for fluid delivery, the piston pump comprising a piston (3), a cylinder member (5), and a pressure chamber (5.2) disposed between the inlet valve and the discharge valve, And means (10) for throttling fluid flow (18) are provided in said fluid flow (18) downstream of said discharge valve,
The throttle means 10 includes a movable ring disk 14 guided on the cylinder member 5 and the inner diameter of the ring disk is adjusted to the outer diameter of the cylinder member 5, Wherein the axial movement distance of the first throttle body defines a variable first throttle cross-
For the dynamic throttling of the fluid flow 18 guided through the at least one outlet 16.6 between the cover 16 and the cylinder member 5 a preliminary stressing device 12 is mounted on the ring disk 14 ) Against the throttle point (16.4) disposed in the cover (16) in the axial direction. 2. The piston pump of claim 1, wherein the ring disk (14) comprises at least one opening fixedly predetermining a second throttle cross-section. 3. The piston pump of claim 2, wherein the second throttle cross-section is configured such that the volumetric flow of fluid through the second throttle cross-section reaches a predetermined amount within a predetermined temperature range. 4. The piston pump of claim 3, wherein the second throttle cross-section is configured such that the volumetric flow of fluid through the second throttle cross-section reaches a predetermined amount in a temperature range of 0 占 폚 to 120 占 폚. delete 2. A method according to claim 1, characterized in that the pre-stressing device (12) is formed as a spring member and the selected spring characteristic of the pre-stressing device (12) defines an axial travel distance of the ring disk Piston pump. 2. A piston pump as claimed in claim 1, characterized in that the pre-stressing device (12) is formed as a helical spring or a flat spring or a leaf spring or a shaft ring. A piston pump according to claim 1, characterized in that the means (5.6) for supporting the pre-stressing device (12) formed as a spring member is formed as a ring shoulder around the cylinder member (5). The piston pump according to claim 1, wherein the end face of the cover (16) forms the throttle point (16.4). A vehicle brake system comprising at least one piston pump according to any one of claims 1 to 4.

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